1. Field of the Invention
The present invention relates to d laminated ink-jet recording head that includes an actuator unit, which is formed of ceramics, and a flow path substrate, which is formed of metal, that are connected to each other.
2. Related Art
In Japanese Unexamined Patent Publication No. Hei 6-40035, an ink-jet recording head is disclosed in which a piezoelectric vibration plate is bonded to an area of an elastic plate to form a pressure generation chamber, and in which to generate ink drops, the volume of the pressure generation chamber is varied by the flexing displacement of the piezoelectric vibration plate. This recording head is characterized in that it is able to generate ink drops stably because of the wide area of the pressure generation chamber that is variable.
In a recording head of this type, normally, an actuator unit, which is formed of ceramics and which includes a pressure generation chamber, a vibration plate and a piezoelectric vibration plate, is fixed by a bonding layer to a single flow path forming unit, which is made of a metal plate and which is so formed as to correspond to a plurality of nozzle openings which are formed in lines.
For such bonding, an adhesive, for example, can be used. However, when an adhesive is used, some accompanying problems arise. For example, the adhesive is not only difficult to apply, but it also may flow into and seal the nozzle openings and a lot of time is required for the adhesive to harden.
On the other hand, to solve these problems, and in particular, to simplify the application operation and to shorten the hardening time, a thermally fusible film is also used for such bonding. In this case as well, however, when pressure is applied to the thermally fusible film during the bonding operation, the thermally fusible film can be compressed and flattened to an unnecessary extent so that bonding layer thicknesses vary, or the film can flow into communication holes and close them. Further, there is a possibility that the thermally fusible film will now be sufficiently compressed and that a part of the film will be unevenly shaped. Then, when the unevenly shaped film is interposed between the substrates to bond them together, a sufficient bonding strength cannot be obtained.